Update some stale comments (#1036)

Author: k-sareen

src/memory_manager.rs

@@ -220,7 +220,7 @@ pub fn post_alloc<VM: VMBinding>(
 /// For a correct barrier implementation, a VM binding needs to choose one of the following options:
 /// * Use subsuming barrier `object_reference_write`
 /// * Use both `object_reference_write_pre` and `object_reference_write_post`, or both, if the binding has difficulty delegating the store to mmtk-core with the subsuming barrier.
-/// * Implement fast-path on the VM side, and call the generic api `object_reference_slow` as barrier slow-path call.
+/// * Implement fast-path on the VM side, and call the generic api `object_reference_write_slow` as barrier slow-path call.
 /// * Implement fast-path on the VM side, and do a specialized slow-path call.
 ///
 /// Arguments:
@@ -244,7 +244,7 @@ pub fn object_reference_write<VM: VMBinding>(
 /// For a correct barrier implementation, a VM binding needs to choose one of the following options:
 /// * Use subsuming barrier `object_reference_write`
 /// * Use both `object_reference_write_pre` and `object_reference_write_post`, or both, if the binding has difficulty delegating the store to mmtk-core with the subsuming barrier.
-/// * Implement fast-path on the VM side, and call the generic api `object_reference_slow` as barrier slow-path call.
+/// * Implement fast-path on the VM side, and call the generic api `object_reference_write_slow` as barrier slow-path call.
 /// * Implement fast-path on the VM side, and do a specialized slow-path call.
 ///
 /// Arguments:
@@ -270,7 +270,7 @@ pub fn object_reference_write_pre<VM: VMBinding>(
 /// For a correct barrier implementation, a VM binding needs to choose one of the following options:
 /// * Use subsuming barrier `object_reference_write`
 /// * Use both `object_reference_write_pre` and `object_reference_write_post`, or both, if the binding has difficulty delegating the store to mmtk-core with the subsuming barrier.
-/// * Implement fast-path on the VM side, and call the generic api `object_reference_slow` as barrier slow-path call.
+/// * Implement fast-path on the VM side, and call the generic api `object_reference_write_slow` as barrier slow-path call.
 /// * Implement fast-path on the VM side, and do a specialized slow-path call.
 ///
 /// Arguments: